Aerosol antiperspirant compositions

ABSTRACT

An aerosol antiperspirant composition comprising: 
     (a) from about 2% to about 10% of a hydrophobic liquid; 
     (b) from about 20% to about 95% of a propellant; 
     (c) from about 2% to about 30% of an enhanced efficacy metallic antiperspirant material, containing at least about 30% of a high efficacy metallic species (by weight of all metallic species in said antiperspirant material); 
     (d) from about 0.1% to about 3.0% of a hydrophobically-treated clay suspension agent; and 
     (e) from about 0.01% to about 0.2% of an activator.

This is a continuation of application Ser. No. 171,619, filed on Mar.22, 1988, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to aerosol antiperspirant compositions, andcompositions for making them. More particularly, it relates tocompositions having high efficacy and improved suspension stability.

Compositions designed to stop or reduce the flow of human perspirationare well known in the cosmetic and chemical literature. Antiperspirantstypically contain an astringent material, such as an astringent aluminumor zirconium salt. The compositions are designed to deliver the activeto the skin in an effective form; while being cosmetically acceptable.

Many antiperspirant compositions contain the antiperspirant activematerial in particulate form, suspended in an anhydrous liquid. Thesecompositions are typically applied to the skin as sprays (both aerosolsand non-pressurized pump sprays) and roll-ons. Many liquid formulationsare described in S. Plechner, "Antiperspirants and Deodorants" 2Cosmetics, Science and Technology 373-416 (M. Balsam and E. Sagarin,editors, 1972). Such compositions are also described, for example, inBritish Patent Specification No. 1,341,618, published Dec. 28, 1973;British Patent Specification No. 1,341,618, published Dec. 28, 1973;British Patent Specification No. 1,341,748, published Dec. 28, 1973;U.S. Pat. No. 4,278,655, Elmi, issued July 14, 1981; and European PatentSpecification No. 28,853, Beckmeyer et al., published June 20, 1981.

Antiperspirant compositions have also been described in the literaturecontaining active materials with improved efficacy. These preferredactives have a selected distribution of polymeric aluminum metal species(containing aluminum with and without zirconium), resulting in improvedantiperspirant efficacy. Such actives, and compositions containing them,are described, for example, in U.K. Patent Application No. 2,048,229,Fitzgerald et al., published Dec. 10, 1980; U.S. Pat. No. 4,359,456,Gosling et al., issued Nov. 16, 1982; U.K. Patent Application No.2,144,992, Calalghan et al., published Mar. 20, 1985; European PatentPublication No. 183,171, Murray et al., published June 4, 1986; andEuropean Patent Publication No. 191,628, Inward et al., published Aug.20, 1986.

It has been found that aerosol antiperspirant, containing preferredactives with suspension agents typically used in the art, may be subjectto clogging. It has also been found that this clogging is particularlyacute with preferred, high efficacy actives having selected polymericdistribution. Therefore, such compositions may be difficult orimpossible to dispense from conventional aerosol containers.

It has been found that the compositions of the present invention containhighly efficacious antiperspirant actives, with selected polymericdistribution, selected hydrophobically-treated clays and specific levelsof activator (based on the clay level) avoid this problem. Compositionsof this invention also provide improved redispersibility (i.e., theability to resuspend the antiperspirant active after settling.)

All percentages and ratios herein are by weight unless otherwisespecified. Additionally all measurements are made at 25° C. unlessotherwise specified.

SUMMARY OF THE INVENTION

This invention provides liquid antiperspirant suspensions comprising:

An aerosol antiperspirant composition comprising:

(a) from about 2% to about 10% of a hydrophobic liquid;

(b) from about 20% to about 95% of a propellant;

(c) from about 2% to about 30% of an enhanced efficacy metallicantiperspirant material, containing at least about 30% of a highefficacy metallic species (by weight of all metallic species in saidantiperspirant material);

(d) from about 0.1% to about 3.0% of a hydrophobically-treated claysuspending agent; and

(e) from about 0.01% to about 0.2% of an activator.

Preferably the level of activator is less than about 0.195% for ahectorite clay and less than about 0.03% for a bentonite clay.

DESCRIPTION OF THE INVENTION

The antiperspirant compositions of this invention encompass as aerosolcompositions intended for human use in order to deposit antiperspirantmaterials on human tissue. They may also contain certain optionalcomponents, such as, for example, cosmetic powders, colorants, perfumesand emulsifiers. The essential and optional components included in thesecompositions must be "cosmetically acceptable", i.e., safe for human useand aesthetically acceptable at the levels encompassed by the presentinvention, at a reasonable risk/benefit ratio.

In particular, these antiperspirant compositions comprise:

An aerosol antiperspirant composition comprising:

(a) from about 2% to about 10% of a hydrophobic liquid;

(b) from about 20% to about 95% of a propellant;

(c) from about 2% to about 30% of an enhanced efficacy metallicantiperspirant material, containing at least about 30% of a highefficacy metallic species (by weight of all metallic species in saidantiperspirant material);

(d) from about 0.1% to about 3.0% of a hydrophobically-treated clay;

(e) from about 0.01% to about 0.2% of an activator.

Preferably the level of activator is less than about 0.195% for ahectorite clay and less than about 0.03% for a bentonite clay.

Preferably, the hydrophobic liquid carrier is present at a level of fromabout 4% to about 7%. The antiperspirant active material is preferablypresent at a level of from about 6% to about 12%. When thehydrophobically-treated suspending agent is a hectorite clay, it ispreferably present at a level of from about 0.2% to about 0.8%. When thesuspending agent is a bentonite clay, it is preferably present at alevel of from about 0.1% to about 0.4%. Preferably the activator ispresent at a level of from about 0.03% to about 0.2%, more preferablyfrom about 0.04% to about 0.06%.

Preferably, the compositions of this invention are essentially free(i.e., containing less than about 1%) of free (not chemically-bound)water. Preferably, then, the antiperspirant active material and othermaterials of this invention are dried so as to avoid introduction ofwater into the composition.

COMPONENTS Hydrophobic Liquid Carrier

The compositions of this invention contain a non-aqueous liquid (herein"hydrophobic liquid carrier") in which a particulate antiperspirantmaterial is suspended. Such hydrophobic liquid carriers are well knownin the art. Hydrophobic liquid carriers among those useful in thisinvention include fatty acid and fatty alcohol esters, water-insolubleethers and alcohols, polyorgano silicones, and mixtures thereof. Suchcarriers are disclosed in the following patent documents, incorporatedby reference herein: U.S. Pat. No. 4,053,851, Pader et al., issued Oct.11, 1077; U.S. Pat. No. 4,065,564, Miles, Jr. et al., issued Dec. 27,1977; U.S. Pat. No. 4,073,880, Pader et al., issued Feb. 14, 1978; U.S.Pat. No. 4,278,655, Elmi, issued July 14, 1981; and British PatentApplication No. 2,018,590, Elmi et al., published Oct. 24, 1979.

Volatile silicone oils are preferred hydrophobic liquid carriers usefulin the present compositions. (As used herein, "volatile" refers to thosematerials which have a measurable vapor pressure at ambient conditions).Such volatile silicone oils may be cyclic or linear. A description ofvarious volatile silicone oils is found in Todd, et al., "VolatileSilicone Fluids for Cosmetics", 91 Cosmetics and Toiletries, 27-32(1976), incorporated by reference herein. Preferred volatile siliconeoils include those having from about 3 to about 9 silicon atoms,preferably containing from about 4 to about 5 silicon atoms. Cyclicvolatile silicones useful herein include those of the following formula:##STR1## wherein n=3 to 7. Linear volatile silicone oils include thoseof the formula:

    (CH.sub.3).sub.3 Si--O--[Si(CH.sub.3).sub.2 --O].sub.n --Si(CH.sub.3)

wherein n=1 to 7. Linear volatile silicones generally have viscositiesof less than about 5 centistokes at 25° C., whereas the cyclic siliconeshave viscosities of less than about 10 centistokes. Examples of volatilesilicone oils useful in the present invention include: Dow Corning 344,Dow Corning 345 and Dow Corning 200 (sold by Dow Corning Corporation);7207 and 7158 (sold by General Electric Company); and SWS-03314 (sold bySWS Silicones Corporation).

Preferably the present compositions contain from about 0.2% to about 7%of one or more liquid emollients as part of the hydrophobic liquidcarrier. These emollients can be either a non-volatile silicone or aliquid paraffin material such as mineral oil. Such materials have aviscosity of from about 5 to about 2,500,000 centistokes, preferablyfrom about 10 to about 100,000 centistokes, at 25° C. Preferably, thenon-volatile emollient is a silicone fluid, such as a polyalkylsiloxane, a polyalkylaryl siloxane, or a polyether siloxane copolymer.

The essentially non-volatile polyalkyl siloxanes useful herein include,for example, polydimethyl siloxanes with viscosities of from about 5 toabout 100,000 centistokes at 25° C. Such polyalkyl siloxanes include theVicasil series (sold by General Electric Company) and the Dow Corning200 series (sold by Dow Corning Corporation). Polyalkylaryl siloxanesinclude poly methylphenyl siloxanes having viscosities of from about 15to about 65 centistokes at 25° C. These are available, for example, asSF 1075 methylphenyl fluid (sold by General Electric Company) and 556Cosmetic Grade Fluid (sold by Dow Corning Corporation). Useful polyethersiloxane copolymers include, for example, a polyoxyalkylene ethercopolymer having a viscosity of about 1200 to 1500 centistokes at 25° C.Such a fluid is available as SF-1066 organosilicone surfactant (sold byGeneral Electric Company). Polysiloxane ethylene glycol ether copolymersare preferred copolymers for use in the present compositions.

Enhanced Efficacy Antiperspirant Active

The present compositions contain a particulate metallic antiperspirantmaterial (herein an "enhanced efficacy metallic antiperspirantmaterial", containing at least about 30% of a high efficacy metallicspecies (by weight of all metallic species in said antiperspirantmaterial). The enhanced efficacy metallic antiperspirant materialsinclude the inorganic and organic salts of aluminum, zirconium andmixtures thereof.

Particularly preferred are the aluminum and zirconium salts such asaluminum halides, aluminum hydroxide halides, zirconyl oxide halides,zirconyl hydroxy halides, and mixtures thereof. Preferred aluminum saltsinclude those of the formula

    Al.sub.2 (OH).sub.a Cl.sub.b.xH.sub.2 O

wherein a is from about 2 to about 5; a+b=6; x is from about 1 to about6; and wherein a, b, and x may have non-integer values. Preferablypreferred are aluminum chlorhydroxides referred to as "5/6 basicchlorhydroxide", wherein a=5, and "2/3 basic chlorhydroxide," whereina=4. Processes for preparing aluminum salts are disclosed in thefollowing documents, all incorporated by reference herein: U.S. Pat. No.3,887,692, Gilman, issued June 3, 1975; U.S. Pat. No. 3,904,741, Joneset al., issued Sept. 9, 1975; U.S. Pat. No. 4,359,456, Gosling, et al.,issued Nov. 16, 1982; and British Patent Specification No. 2,048,229,Fitzgerald, et al., published Dec. 10, 1980. Mixtures of aluminum saltsare described in British Patent Specification No. 1,347,950, Shin, etal., published Feb. 27, 1974 (incorporated by reference herein).

Zirconium salts are also preferred for use in antiperspirantcompositions of the present invention. Such salts are of the generalformula

    ZrO(OH).sub.2-a Cl.sub.a.xH.sub.2 O

wherein a is from about 1.5 to about 1.87; x is from about 1 to about 7;and wherein a and n may have non-integer values. These zirconium saltsare disclosed in Belgium Patent No. 825,146, Schmitz, published Aug. 4,1975, (incorporated by reference herein). Particularly preferredzirconium salts are those complexes also containing aluminum andglycine, commonly known as "ZAG complexes". Such ZAG complexes containaluminum chlorhydroxide and zirconyl hydroxychloride of the formulaedetailed above. These compounds in ZAG complexes are disclosed in U.S.Pat. No. 3,679,068, Luedders, et al., issued Feb. 12, 1974 (incorporatedherein by reference), and U.S. Pat. No. 4,120,948, Shelton, issued Oct.17, 1978 (incorporated by reference herein).

These metallic astringent salts are comprised of a mixture of metallicspecies, i.e., containing metallic ratios of different valences. Asdescribed in the literature, the antiperspirant efficacy of thesespecies may vary. In particular, specific aluminum-containing species(herein, a "preferred metallic species") have been found to haveenhanced antiperspirant efficacy in aluminum chlorhydrate andzirconium-aluminum complexed actives. The enhanced efficacy metalantiperspirant actives of this invention contain at least about 30% (byweight of all metal-containing species) of such preferred antiperspirantspecies.

"Enhanced efficacy aluminum chlorhydrates" among those useful herein aredescribed in the following patent documents, all incorporated byreference herein: U.K. Patent Application No. 2,048,229, Fitzgerald etal., published Dec. 10, 1980; U.S. Pat. No. 4,359,456, Gosling et al.,issued Nov. 16, 1982; European Patent Application No. 183,171, Murray etal., published June 4, 1986; and European Patent Application No.191,628, Inward et al., published Aug. 20, 1986. These enhanced efficacyaluminum chlorhydrate materials contain a preferred metallic speciesthat is the third aluminum fraction isolated (or detected) in sizeexclusion chromatography of the aluminum chlorhydrate material. Thisspecies is described as the "Band III" species in U.S. Pat. No.4,359,456, incorporated herein by reference. Chromatographic methodsuseful in identifying such aluminum-containing species are alsodescribed in the '456 Patent.

The enhanced efficacy aluminum chlorhydrates of the present compositionscontain at least about 30%, preferably at least about 40% (by weight ofall aluminum species in said material), of the preferred metallicspecies. Also preferably, the enhanced efficacy aluminum chlorhydratesof this invention contain less than about 20%, more preferably less thanabout 10%, more preferably less than about 1% (by weight of all aluminumspecies in said material), of the first aluminum fraction isolated insize exclusion chromatography of the aluminum chlorhydrate material.

Enhanced efficacy zirconium-aluminum complex actives among those usefulin this invention are described in U.K. Patent Application No.2,144,992, Callaghan et al., published Aug. 16, 1983. Size exclusionchromatography of these enhanced efficacy aluminum-zirconium activestypically yields five metal containing species. The enhanced efficacyzirconium-aluminum actives of this invention contain at least about 30%(by weight of all metal species in said material) of the fourth metallicspecies isolated by size exclusion chromatography of said material.

Hydrophobically-treated Suspending Clay Agents

The compositions of this invention contain selectedhydrophobically-treated clays as suspending agents. As discussed above,use of these selected clays avoids formation of sludge. The suspendingagents useful herein include hydrophobically-treated montmorilloniteclays, e.g., bentonites and hectorites. Many such clay suspension agentsare commercially available. They include, for example, Bentone 38(hectorite) and Bentone 34 (bentonite) sold by NL Industries, Inc., andTixogel (bentonite) sold by United Catalyst, Inc.

The hectorite and bentonite clay minerals of the instant compositionscan be described as expandable (swellable), three-layer clays, in whicha sheet of aluminum/oxygen atoms or magnesium/oxygen atoms lies betweentwo layers of silicone/oxygen atoms, i.e., aluminosilicates andmagnesium silicates, having an ion exchange capacity of at least about50 meq/100 g. of clay, and preferably at least about 60 meq/100 g. ofclay. The term "expandable" as used to describe clays relates to theability of the layered clay structure to be swollen or expanded oncontact with water. Such hectorite and bentonite clays are described inGrim, Clay Mineralogy (2nd. Ed.) pp. 77-79 (1968), and in Van Olphen, AnIntroduction to Clay colloid Chemistry, (2nd Ed.) pp 64-76 (1977), bothof which are incorporated by reference herein.

The clay minerals employed in the compositions of the instant inventioncontain exchangeable cations including, but not limited to, protons,sodium ions, potassium ions, calcium ions, magnesium ions, lithium ions,and the like.

It is customary to distinguish between clays on the basis of one cationpredominantly or exclusively absorbed. For example, a sodium clay is onein which the absorbed cation is predominantly sodium. As used herein,the term clay, such as a hectorite clay, includes all the variousexchangeable cation variants of that clay, e.g. sodium hectorite,potassium hectorite, lithium hectorite, magnesium hectorite, calciumhectorite, etc.

The clay minerals employed in the compositions of the instant inventionare made hydrophobic by treating them with a cationic surfactantmaterial. A preferred cationic surfactant is a quaternary ammoniumcationic surfactant. A particularly preferred cationic surfactant isditallow dimethyl ammonium chloride (e.g., quaternium-18).

Suspension Agent Activator

The compositions of this invention contain an "activator" for thehectorite and bentonite clays that enables the hydrophobically-treatedclays of this invention to suspend the antiperspirant active in thehydrophobic liquid carrier. Many such activators are known in the art.Such activating materials include, for example, propylene carbonate,ethanol, and mixtures thereof.

Preferably the level of activator is less than about 0.195% for ahectorite clay and less than about 0.03% for a bentonite clay.

Without being limited by theory, it is believed that this level ofactivator will activate the clay without causing bridging betweenparticles of active and particles of clay forming agglomerates that canlodge in the valve.

Optional Components

The compositions of the present invention may also contain optionalcomponents that modify the physical characteristics of the vehicles orserve as "active" components when deposited on the skin in addition tothe particulate antiperspirant material. Additional active componentsinclude bacteriostats and fungistats. Optional components useful hereinare described in the following patent documents, all incorporated byreference herein: U.S. Pat. No. 4,049,792, Elsnau, issued Sept. 20,1977; and European Patent Specification No. 28,853, Beckmeyer, et al.,published June 20, 1981. The particular non-active components that maybe useful will depend upon the form of application that is desired. Suchcomponents include, for example, emollients, colorants, perfumes, andemulsifiers.

METHODS

The compositions of this invention may be made by a variety of methodswell known in the art. The specific methods employed may vary, ofcourse, according to the particular components used. A preferred methodfor making aerosol compositions of this invention, for delivery from asuitable aerosol container, comprises the steps of:

(a) preparing a concentrate by mixing and milling the hydrophobic liquidcarrier, the clay suspending agent, and activator; and adding theenhanced efficacy antiperspirant material to the mixture either beforeor after milling;

(b) filling the concentrate into the container; and

(c) pressurizing the container by adding a propellant into the containerand sealing the container.

The following non-limiting examples illustrate the compositions,processes and uses of the present invention.

EXAMPLE 1

An antiperspirant aerosol of this invention is made comprising

    ______________________________________                                        Component        % (by weight)                                                ______________________________________                                        Cyclomethicone   6.95                                                         Dimethicone      1.00                                                         Isopropyl myristate                                                                            0.50                                                         REACH 101.sup.1  9.00                                                         Tixogel VP       0.56                                                         Propylene carbonate                                                                            0.03                                                         Fragrance        0.20                                                         A-46 propellant.sup.2                                                                          81.60                                                        ______________________________________                                         .sup.1 enhanced efficacy aluminum chlorhydrate, manufactured by Reheis        Chemical Corporation, having approximately 40% (by weight of aluminum         species) of preferred metallic species (Band III aluminumcontaining           chromatographic species) and approximately 0% of Band I aluminumcontainin     chromatographic species                                                       .sup.2 volatile propellant, mixture of 87% isobutane and 13% propane (by      weight of total propellant)                                              

An antiperspirant aerosol is made by admixing the concentratecomponents. The concentrate, including active, was then milled underhigh shear conditions. The concentrate components were added to astandard aerosol can. The propellant and fragrance were then added,under pressure, and the can sealed.

EXAMPLE 11

The product, when applied to the underarm area of a human subject, iseffective as an antiperspirant.

    ______________________________________                                        Component        % (by weight)                                                ______________________________________                                        Cyclomethicone   6.0                                                          Isopropyl myristate                                                                            4.0                                                          Westwood DM-200.sup.1                                                                          8.0                                                          Bentone-38       0.8                                                          Propylene carbonate                                                                            0.1                                                          A-31 propellant.sup.2                                                                          81.1                                                         Fragrance        0.2                                                          ______________________________________                                         .sup.1 enhanced efficacy aluminum chlorohydrate manufactured by Westwood      Chemical Corporation, having approximately 40% (by weight of aluminum         species) of preferred metallic species (Band III aluminumcontaining           chromatographic species) and approximately 0% of Band I aluminumcontainin     chromatographic species                                                       .sup.2 mixture of 96% isobutane and 3% nbutane                           

An antiperspirant aerosol is made by combining the components asdescribed above in Example I.

The product, when applied to the underarm of a human subject, iseffective as an antiperspirant.

What is claimed is:
 1. An aerosol antiperspirant compositioncomprising:(a) from about 2% to about 10% of a hydrophobic liquidselected from the group consisting of fatty acid and fatty alcoholesters, water-insoluble ethers and alcohols, polyorganosilicones, andmixtures thereof; (b) from about 20% to about 95% of a propellant; (c)from about 2% to about 30% of an enhanced efficacy metallicantiperspirant material containing at least about 30% of a high efficacymetallic species (by weight of all metallic species in saidantiperspirant material); (d) from about 0.1% to about 3.0% of ahydrophobically-treated bentonite or hectorite clay suspension agent;and (e) an activator selected from the group consisting of propylenecarbonate, ethanol, and mixtures thereof, wherein the level of activatoris from about 0.01% to about 0.195% when the suspension agent is saidhectorite clay and from about 0.01% to about 0.03%, when the suspensionagent is a bentonite clay.
 2. An antiperspirant composition according toclaim 1, wherein said activator is propylene carbonate.
 3. Anantiperspirant composition according to claim 1, wherein said suspensionagent is a hectorite clay and said activator is present at a level offrom about 0.04% to about 0.06%.
 4. An antiperspirant compositionaccording to claim 2, wherein said enhanced efficacy metallicantiperspirant material is an enhanced efficacy aluminum chlorhydrate.5. An antiperspirant composition according to claim 4, wherein saidenhanced efficacy aluminum chlorhydrate contains at least about 40% (byweight of all aluminum species in said aluminum chlorhydrate) of thepreferred metallic species.
 6. An antiperspirant composition accordingto claim 5 wherein said suspending agent is a bentonite clay.
 7. Anantiperspirant composition according to claim 5, wherein said enhancedefficacy aluminum chlorhydrate contains less than about 1% (by weight ofall aluminum species in said aluminum chlorhydrate) of the firstaluminum fraction isolated in size exclusion chromatography of saidaluminum chlorhydrate.
 8. An antiperspirant composition according toclaim 2, wherein said enhanced efficacy aluminum chlorhydrate is anenhanced efficacy zirconium-aluminum complex.
 9. An antiperspirantsuspension composition according to claim 2, wherein said hydrophobicliquid carrier comprises said polyorganosilicone.
 10. A method formaking an aerosol antiperspirant composition according to claim 1, fordelivery from a suitable aerosol container, comprising the steps of:(a)preparing a concentrate by mixing and milling said hydrophobic liquidcarrier, said activator and said clay suspending agent; and adding saidenhanced efficacy antiperspirant material to the mixture of saidmaterials either before or after said milling; (b) filling saidconcentrate into said container; and (c) pressurizing said container byadding said suitable aerosol propellant into said container and sealingsaid container.